Reaction products of poly (alkylenoxy) alkyl 1-aziridinecarboxylates with polyamines



United States Patent "cc Patented iififfil? wherein R is an alkyl group of from 1 to18 carbon atoms 3,359,303 or a group of the formula REACTION PRODUCTS 0F POLY(ALKYLENOXY) ALKYL 1 AZIRIDINECARBOXYLATES WITH POLYAMINES William P. Coker and Robert E. Lane, J12, Lake Jackson, 5 H

Tex., assignors to The Dow Chemical Company, Midland, Mich, a corporation of Delaware H No Drawing. Filed Jan. 31, 1964, Ser. No. 341,773 H\ 3 Claims. (Cl. 260-482) This invention relates to new compositions of matter M and to the preparation of such compositions. More particularly, the present invention relates to carbamates which contain a plurality of ether linkages, to the preparation of such carbamates and to the use of these carbamates in the production of cured materials based upon epoxy resin (eaCh of 1 and 2 is a lowsr aikyi group of from 1 i0 4 compositions, carbon atoms), k is an integer of from 2 to 4 and may The reaction of aniline with cyclohexyl l-aziridinylforhave a diifefeht Value Of each n example, in the mate to produce O-cyclohexyl-N- (B-anilinoethyDurethane p, 2 2 2 2 2 is 2 and k is is disclosed by Iwakura et al. in J. Org. Chem., 25, 1118- n is n i g of 0111 2 t0 each 0 is a hydrogen atom 1123 (1960). Other reactions of various amines with or a lower alkyl group of from 1 to 4 carbon atoms esters of l-aziridinecarboxylic acid are disclosed in French the group f zp-l Where P is an integer of from 1 10 Patent 1,279,318 and in Netherlands Patent 63,864. 4) such as a methyl, ethyl, n-propyl, i-propyl, n-butyl, sec.- It is also known that conventional amine curing agents butyl, iso-butyl or tert.-butyl group, A is a divalent alkyl- (used to promote cross-linking in epoxy resins) are often 25 ene g p of from 2 t0 4 Carbon atoms -gs ethylene, toxic, hygroscopic or skin sensitizing materials which propropylene, trimethylene, tetramethylene, isobutylene, etc.) duce relatively brittle plastic materials upon completion n m is all ihtegfif O from 1 t0 Exampies of suitable of the cure cycle. Various methods have been tried in R groups include lower alkyl groups as previously deattempts to reduce the brittleness of such compositions. fin d an a hexyl, heptyl, octyl, nonyl, decyl, undecyl, For example, curing agents which contain an SS linky ififiecyi, r yl, p n y h y ep age or adducts formed by the reaction of amines and decyl or octadecyl group. vegetable oil acids have been employed. Such substances Typical polyamine compounds which may be reacted may reduce the brittleness of the cured plastic, but often With the alkylenoxy l-aziridinecarboxylates according to the resulting product is more sensitive to certain hydro- Equation I include eihyieflediamihe, dieihyieneiriamihe, carbon solvents (such as toluene). Similarly, hardeners tetraethylenepentamine,triethylenetetramine,1,3-propanewhich are of reduced toxicity usually contain hydroxyl diamme,1, ahd'lrz-pfopallediamihef groups in the molecule, and the presence of these hydroxyl The carbamate curing materials of the invention are groups tends to increase solvent absorption properties of prepared by mixing a poly(alkylenoxy)alkyl ester of 1- the resulting cured product. aziridinecarboxylic acid as defined in Equation I and a It has now been found that a new class of carbamates, 0 polyamine in a mole ratio of about 1:1. Mole ratios of which contains ether linkages but no hydroxyl within the from about 1.5 :1 to .5 :1 (poly(alkylenoxy)alkyl ester molecule, can be prepared by the reaction of a polyamine of l-aziridinecarboxylic acid: polyamine). may be used, and a polyether which contains a l-aziridinylformate but it is preferable to employ amounts of reactants suffigroup. The novel earbamates which are produced by this cient to provide as close to a stoichiornetric ratio as posreaction are excellent curing agents for epoxy resins and le in th r a ti n Z n Th r acti n may be Carried produce cured plastics with superior physical and chemiout at temperatures of from about 0 to 150 C. for time cal properties when compared with compositions formed Periods 0f from about to 10 hours- It is Pfsferabie with conventional curing agents (such as the standard to Carry Out the reaction at temperatures of from to diethylenetriamine-epoxy resin system). Cured epoxy resin 60 C. for a period of time suflicient to form the desired compositions prepared with the compounds of the inven- C a t s lly from 1 t0 3 The reaction tion are generally more flexible than the corresponding may be carried out at any pressure of from 0.1 to 100 plastics obtained with conventional amine curing agents. p.s.i. The reaction is generally carried out at atmospheric In addition, the properties of the cured epoxy resins can pressure using an inert solvent and/or an inert atmosphere be controlled by variation of both the number and kind u as nitr g n)- AS u ed herein, the term p0ly(alkyl 0f alkoxy groups and/or alkylenoxy groups in the moleenoxy)alkyl ester of l-aziridinecarboxylic acid is meant cule. to represent the esters defined in Equation I and includes The novel curing agents of the invention may be prethose esters in which the aziridine ring is substituted or pared according to the following reaction u su stituted.

The starting polyalkylenoxy esters of l-aziridinecar- 0 boxylic acid are prepared by the reaction of'a polyalkylenoxy alcohol and phosgene to form the corresponding (I) R chloroformate. Reaction of the chloroformate with an 3 4 yields the ester of l-aziridinecarboxylic acid used as a [2,2-bis(4-(2,3-epoxypr0poxy)phenyl)propane]. Other starting material in the present invention. The polyalkylcross-linking agents, modifiers and reactive diluents may enoxy alcohols are prepared by conventional methods be used in addition to the curing agents of the present in- (i.e., oxyalkylation of hydroxyl-containing compounds) vention. such as are disclosed in United States Patents 2,841,479 The following examples are submitted for the purpose and 2,782,240 (both by Hefner et al.). of illustration only and are not to be construed as limiting The following reactions further illustrate the invention: the scope of the invention in any way.

0-011: 0 H CH3 CH H f II I CHacHi0-\CHioH,0 C-N\ HzNCHaCHzNHa CHQCHzOTCHhCHzOTC-N(E?-NCH:CH:NH1

A (ll-CH3 H H CHaO CH\2H H /CH2 o-o-{cnno} (031100} CN\l HaN\ OH2CHzN-/H 011101110015 y on a H i /GOG;H,0 C3HQO}CN'CH2OH7N \CHlCH2N-H omcrno CH1 y a t? F" C H 7O- CH:CHzO -C;H O -C--N HzNCHzCH2NCHzCH:CHg-NH1 I I C1gH370 CH2CH20 0 3E 0 -g-N-CHzCHr-N-CH:CHIICH:CHzCHzNHa ('r and s are integers such that the sum of r+s is from about 2 to In the above equations, it is to be understood that the Exiample 1 different alkylenoxy groups may be in any order in the chain, e.g., -(C H O-) {C H O-) includes groups such as The cured epoxy resin compositions are prepared by II I CH 0 mixmg the carbamates of the inventlon with the epoxy C resin in amounts suflicient to obtain cross-linking of the resin. Any resin with curable epoxy groups may be used. A 91-92 196mmt P (based 0!! nyl ontent) Epoxy resins which are f d by the reaction of an liquid 2-(2 -ethoxyethoxy)ethyl ester of l-aziridinecarepihalohydrin and Bisphenol-A (polyglycidyl polyethers bOXYhC and (prepared by reacting diethylene g y ol of Bisphenol-A) are preferred. An amount of carbamate {nonoethyl ether with Phosgene to form the p n compound sufficient to provide one active hydrogen atom mg chloroformate, followed the reaction Of this ChlOl'O- (bonded to aminonitrogen) per epoxy group of the resin formats With ethylenimifle) Was added I Wly dropwise is usually employed. The hydrogen atom on the carbamate grams; H1016) t0 ethylenediamine g 0 CH1 CHaCHnO-CHgCHaOCHzCHrO-C-N\ I HzNCHzCHzNHz ---D 45 CH:

nitrogen is not an active hydrogen atom. The stoichiomet- 111016) at lmdel y nitrogen in the Same rig amount of carbamate per hu d d parts i h of reactor used for the preparation of the chloroformate resin is obtained by dividing the amino hydrogen equivaand aziridmecarboxylate. The reaction mixture was stirred lent weight by the epoxide equivalent weight of the resin for one hour at then Cooled The P and multiplying this ratio by 100. The epoxy resin may be 306-4 grams of a Water clear liquid 4 had cured at ambient room temperatures over a period of seva reffaCtiVfi index Na D ne) of 1.4750 and a eral days or may be cured in less than an hour with temviscosity of 120 centipoises at 25 C.

peratures of about 90-110 C. Suitable polyglycidyl Reaction of 118 grams of this product with 188 grams polyethers of Bisphenol-A [2,2-bis (4-hydroxyphenyl)pro- 65 of DER331 epoxy resin, a liquid epoxy resin having an pane] may be represented by the formula epoxy equivalent weight of 188, manufactured by The wherein m is a number of from 0 to 20, depending upon Dow Chemical Company, at 80 C. overnight gave a plasthe desired viscosity or melting point of the resin. When tic having a tensile strength of 1143 p.s.i., 64.7 percent m is zero, the diglycidyl ether of Bisphenol-A is obtained elongation, 4.97 ft. lb./in. impact strength and a Shore D hardness of 31. It absorbed only 3 percent of its initial weight of toluene in 24 hours.

In a procedure and with an apparatus similar to that of Example I, 215.4 grams (0.97 mole) of the 2-(2-ethoxyethoxy)ethyl ester of l-aziridinecarboxylic acid was reacted with 184 grams (0.97 mole) of tetra-ethylenepenta- CHQO CH2 H C CHsOC mine. The resulting product (393 grams of a clear yellow liquid, d =1.11O2) had a refractive index (20 C. Na D line) of 1.4954 and a viscosity of 410 centipoises at 25 C.

Reaction of 86 grams of this product with 188 grams of DER-331 epoxy resin gave a plastic having a tensile strength of 10,900 p.s.i., 9.6 percent elongation, 1.08 ft. lb./in. impact strength, Shore D hardness of 84.5 and no absorption of toluene in 24 hours.

(x and y are from 2 to and indicate the number of alkylenoxy groups, but not the relative order, in the molecule).

The starting polyalkylenoxy ester of l-aziridinecarboxylic acid was prepared by first reacting a mixture of equimolar amounts of ethylene oxide and propylene oxide with 1,3-dimethoxy-2-propanol as a polymerization initiator. The resulting product (a polyalkylenoxy alcohol with a 1,3-dimethoXy-2-propoxy end group) was a clear oil and had a molecular weight of 473 (trademark Ambiflo Hl9.1, available from the Dow Chemical Company). This product (526 grams) was reacted with 54 grams of ethylenimine in the presence of 124 grams of triethylamine and 1800 milliliters of benzene solvent. After removal of the volatile components of the reaction mixture, 457.5 grams of a yellow oil remained (the corresponding polyalkylenoxy alcohol ester of l-aziridinecarboxylic acid). The oily product (d =1.-101) contained 97.6 percent of the theoretical amount of the aziridinyl group and had a refractive index C., Na D line) of 1.4578. A sample of this material (220.4 grams; 0.381 mole) was added dropwise to diethylenetriamine (39.2 grams; 0.381 mole) using a procedure and equipment similar to that employed in the preceding examples. The reaction temperature was 45 to 65 C. The carbamate product (240.6 grams of a very light yellow, somewhat cloudy, liquid; d =1.068) had a refractive index of 1.4724 (20 C. Na D line) and a viscosity at 25 C. of 540 centipoises. The actual amino hydrogen equivalent weight was 161 grams (theoretical equivalent weightz161 grams).

The carbamate product was reacted with DER-331 epoxy resin in a weight ratio of 161 grams of carbamate per 188 grams of epoxy resin. The resulting cured resin had a tensile strength of 1387 psi, 42 percent elongation, an impact strength of 3.24 ft. lb./in. and a Shore D hardness of 35.

Example IV (x and y are from 2 to 5; ethylene oxide groups may alternate with propylene oxide groups).

In a similar manner, 206 grams (0.357 mole) of the polyalkylenoxy ester of l-aziridinecarboxylic acid (prepared in Example III) was reacted with 67.6 grams (0.357 mole) of tetraet-hylenepentamine at a temperature of from 45 to C. The resulting carbamate product (256.5 grams of yellow liquid) had a refractive index (Na D line, 20 C.) of 1.4801 and a viscosity at 25 C. of 680 centipoises. Reaction of 139 grams of this product with 188 l CHaCHrNTH -e grams of DER-331 epoxy resin gave a cured plastic with a tensile strength of 3920 p.s.i., 15.6 percent elongation, an impact strentgh of 1.5 ft. lb./in. and a Shore D hardness of 71.

(a) R is selected from the group consisting of an alkyl group of from 1 to 18 carbon atoms and a group of 0 the formula RrO-CH H C- R20-C 65 in which each of R and R is a lower alkyl group of from 1 to 4 carbon atoms, (b) each of r and k is an integer of from 2 to 4, (0) each of n and s is an integer of from 1 to 20, such that their sum is 2 to 20, (d) each R is selected from the group consisting of the hydrogen atom and a lower alkyl group, (e) A is a divalent alkylene group of from 2 to 4 carbon atoms, and (f) m is an integer of from 1 to 6.

wherein:

(a) R is selected from the group consisting of an alkyl group of from 1 to 18 carbon atoms and a group of the formula in which each of R and R is a lower alkyl group of from 1 to 4 carbon atoms,

(b) each of r and k is an integer of from 2 to 3,

(c) each of n and s is an integer of from 1 to 20 such that the sum n+s is from 2 to 20, and

(d) m is an integer of from 1 to 6.

3. A compound of the formula 8 6. A compound of the formula CHsOCHz H O H H I 00-c,Hi.0-0-NCH1cHNH A cH=ocH= wherein x is an integer of from 2 to 3, y is from 2 to 5 and z is an integer of from 2 to 6.

7. A compound of the formula wherein xis an integer from 2 to 3 and -y is from 2 to 5.

8. A compound of the formula wherein x is an integer from 2 to 3 and y is from 2 to 5.

References Cited UNITED STATES PATENTS 3,162,618 12/1964: Smith s. 260-775 3,223,681 12/ 1965 Rambosek 260-77.5

FOREIGN PATENTS 63,864 3/ 1949 Netherlands.

67,192 7/1942 Norway.

OTHER REFERENCES Iwakura et al.: I. Organic Chem, vol. 25, pp. 1118- 1123 (1960).

LORRAINE A. WEINBERGER, Primary Examiner.

A. P. HALLUIN, Assistant Examiner. 

1. A COMPOUND OF THE FORMULA R-O-(H2RCR-O)A-(H2KCK-O)N-CO-NH-C(-RO)2-C(-RO)2-NH-(A-NH)MH WHEREIN: (A) R IS SELECTED FROM THE GROUP CONSISTING OF AN ALKYL GROUP OF FROM 1 TO 18 CARBON ATOMS AND A GROUP OF THE FORMULA R1-O-CH2-CH(-CH2-O-R2)IN WHICH EACH OF R1 AND R2 IS A LOWER ALKYL GROUP OF FROM 1 TO 4 CARBON ATOMS, (B) EACH OF R AND K IS AN INTEGER OF FROM 2 TO 4, (C) EACH OF N AND S IS AN INTEGER OF FROM 1 TO 20, SUCH THAT THEIR SUM IS 2 TO 20, (D) EACH R0 IS SELECTED FROM THE GROUP CONSISTING OF THE HYDROGEN ATOM AND A LOWER ALKYL GROUP, (E) A IS A DIVALENT ALKYLENE GROUP OF FROM 2 TO 4 CARBON ATOMS, AND (F) M IS AN INTEGER OF FROM 1 TO
 6. 